Adjuvant powder control for flame cutting



June 24, 1958 A. F. CHOUINARD ETAL 2,840,016

ADJUVANT POWDER CONTROL FOR FLAME CUTTING Original Filed Oct. :51, 19522 Sheets-Sheet 1 Carrier Gas FIGZ To In jector To Torch INVENTORS.

ALFRED E CHOUINARD BY EDWARD SPENCER ATTORNEY June 24, 1958 A. F.CHOUINARD ETAL 2,840,016

ADJUVANT POWDER CONTROL FOR FLAME CUTTING Original Filed Oct. 31, 1952 2Sheets-Sheet 2 x -u 7 4o 8 N) A FIG?) FIG. 4

INVENTORS. ALFRED E CHOUINARD BY EDWARD 'ESPENCER ATTORNEY ADJUVANTPOWDER CONTROL FOR'FLAME CUTTING Alfred F. Chouinard, Chicago,'andEdward Spencer, Cary, 111., assignors to National Cylinder Gas Company,Chicago, Ill., a corporation of Delaware Continuation of applicationSerial No. 317,912, October This application June 11, 1956, Serial No.

4 Claims. (Cl. 110-22 The present invention relates generally to asystemand apparatus for thermochemically cutting metals normally l 2 thecarrier gas flows through branch conduit 14 to injector 16 by way ofautomatically operable carrier gas shut off valve 15.

immune to flame cutting with preheat flames and oxygen I alone. Thecutting method involved proceeds through the action of heating flames, ahigh pressure oxygen stream and flux-forming adjuvant material deliveredwith a carrier gas'to the Work, andthis inventionspecifically providesan improved system for an automatic flow'control of the carrier gas andadjuvant material, such as iron powder. This application containssubject matter in common with copending application Serial No.79.0,562,'filed December 9, 1947, now Patent 2,622,548.

The principal object of this invention is to provide a fully automaticflow control for flux-forming adjuvant material and its carrier gaswhich is simple in construction and operation and yet'is rugged anddependable in operation. g A feature of this invention resides in theprovision of a pneumatically operated flow control means whichsimultaneously controls the flow of powdered adjuvant material andcarrier gas, and which maintains a predetermined powder feed or hopperpressure.

These and other features and advantages of the instant invention willbecome apparent from the description that follows and the accompanyingdrawings, wherein:

Fig. 1 is a diagrammatic showing of a preferred system embodying thisinvention.

Fig. 2 is a plan view of a preferred embodiment control and pressuremaintaining apparatus shown schematically as part of the diagrammaticshowing of Fig. 1.

Figs. 3 and 4 are sectional views both taken on line A-A of Fig. 2,showing that portion of the device in nonoperating or closed andoperating or open positions, respectively.

In the system as diagrammatically shown in Fig.1, there is employed asupply chamber or hopper 10. The hopper '10 may be provided with aremovable top (not Flux forming material or adjuvant powder is drawnfrom the hopper 10 through conduit 17 by the action of an injector 16and is entrained with the carrier gas to flow through carrier gas powderconduit 18 to torch 20 by way of powder flow cut off valve 19.

Torch'20 is supplied with high pressure cutting oxygen from asource (notshown) through conduit 21. by way of torch: cutting oxygen valve 22;with fuel gas, such as acetylene, 'for preheat flames through conduit 23.by way of torch fuel gas valve 24; and with fuel gas combustion oxygenthrough conduit 25 by way of torch valve 26. As these three conduits andtorch valves (21-26) 'are conventional and well known in the art,further description of them is unnecessary.

Downstream of the cutting oxygen torch valve 22 and between it and torch20, there is abranch control conduit 27 connected to apneumatic deviceindicated generally at 28. The operating mechanism of the pneumaticdevice 28 is mechanically linked to simultaneously operate both thepowder flow valve 19 and the carrier gas valve 15, and this mechanicallinkage is schematically indicated at 29 in Fig. 1 by the dotted lineinterconnecting the three members, 28, 19 and 15. i

That portion of the system indicated at 15, 19, 28 and 29 in Fig. 1 maybe conveniently constructed as follows:

Pneumatic device 28 constitutes a motivating means for the valves 15 and19, and comprises a cylinder 30 mounted on a base 31. Cylinder 30 isprovided with a piston 32 (see Figs. 3- and 4) reciprocable therein. Thepiston 32 is connected, for example, by screw 33, to a piston rod34which slidably extends through an opening in cylinder cover 35suitably secured to the cylinder 30 by cap screws 36. The piston 32 isbiased to its normal position away from the cylinder cover 35 by meansof compression spring 37 surrounding the piston rod 34 and positionedwithin the cylinder 30 between the cylinder cap35 and the piston 32.The'outer end of the pistonrod'34 is connected to arm 38 of yoke 39. Theyoke 39 straddles a flexible portion 41 of carrier gas and powderconduit 18. Preferebly, this flexible portion 41 consists of 'a shortlength of; rubber tubing. To obviate possibility of accidentalrestriction of flexible tubing portion 41, it is encased within atprotecting shell or tube 42 of suitably larger diameter but providedwith aperture 43 adjacent arm 40 shown) to facilitate its filling to anydesired extent with Carrier gas for the adjuvant material, which may beessentially nitrogen, and which is preferably a, mixture therewith offrom about 5% to about 38% by volume of hydrogen, issuppliedunderpreselected pressure 'from-a supply source (not shown) throughconduit 11. Part of the carrier gas flows into the hopper 10 through aconventional pressure reducing regulating valve 12 and manually operablepressure release valve 13. The regulator 12 is' preferably preset tomaintain a pressure in the hopper '10 of the order of 5 p. s. i. Therelease valve 13 is provided merely for bleeding the hopper portion ofthe system when removal of the hopper top is necessary or desired forany purpose. As will become apparent later, the arrangement of. thesystem is such as to eliminate the I necessity for pressurestabilization or constant pressure bleed-0E of gas from the. hopper.Another portion-of ofthe yoke 39. In alignment with the opening 43 andconnected to the arm 40 of yoke 39 is a'short plunger 44 having its freeend rounded. In the normal or closed (non-operating) position of thepneumatic device 28 (Fig. 3) the plunger 44 extends through the aperture43 in the shielding shell 42pressing into and closing therubber tubingsection 41 of the conduit 18 under the tension of the compression spring37. a

Adjacent the other side of the yoke arm 40 from which the plunger 44extends is the end of a plunger 45 which extends from a somewhat bellshaped casing 460i the carrier gas valve 15.

The casing 46 is also mounted on the base 31 and the plunger 45 isarranged to reciprocate within a suitably packed gland nut 47 closing anopening 48 in casing 46 provided for this purpose. Within the casing 46of'valve 15 are two chambers 49 and 50 with a communicating valvepassage 51 therebetween. The chamber 49 is con- 1 nected with the inletside of conduit 14 while chamber 50 is connected to the outlet sideleading to the injector 16. The plunger .45 extends through the passage'51 and terminates in a valve member 52 within chamber 50 normallyclosing passage 51. The normally closed position of valve 15 is insuredby compression spring 53 between Patented June 24, s

valve body 52 and casing 46 biasing valve bodv 52 into. closed positionrelative to the passage 51.

Operatin I H The operation of this-system is extremely simplezandcorrespondingly rugged and dependable. Theregulator 1 2 is set tocontrol and maintain thedesiredpreselected pressure, in powder hopper10.v Torch valve 24 isopened and the fuel gas is ignited. gfoxygen valve26 is then opened and valves 24 and 26 {are adjusted to obtain desiredheating flames. Atteriheworlt is suitably preheated and it is desired tobegin the cut, only the cutting oxygen valve 22 need be manipulated. Assoon as the valve 22 is opened,-p'ressure in conduit 21 is transferredby the control conduit 27 to cylinder 30. Pressure behindpiston32 movesthe piston to the position illustrated in the sectional view of Fig. 4.Piston rod 34 and yoke 39 move to the right as viewed in the drawingwithdrawing plunger .44 from shell 42' thus opening tubing 41.Simultaneously, the yoke arm 40 moves gas valve plunger45 and valve body50 to the right thereby opening valve passage 51. Carrier gas flowsthrough gas valve and through the injector 16 causing adjuvant powder'to be entrained with carrier gas and delivered through conduit 18 andthe'powder valve section or tubing 41. to the torch 20. 7

When the cut is completed or should it be desired to halt the cutting,only the, cutting oxygen valve. 22 need be closed. The pressure incylinder of pneumatic device 28 immediately bleeds off through thetorch, and the compression springs 37 and 50 restore piston 32 and valvebody 52, respectively, to their positions shown in Fig. 3 therebystopping the flow of powder through rubber ,tubingfisection 41 of thepowder flow valve 19 and closing valve passage 51in the gas valve 15 tofurther passage of carrier gas to the injector 16. With both'the valves15 and 19 instantaneously closed, the higher pressure in carrier gasconduit 14 cannot bleed into or cause any increase in the desired powderdelivery pressure within hopper- 10. Moreover, the carrier gas withinthe hopper 10is not permitted to bleed off through the injector to thetorch because'the valve 19 is also closed. Accordingly, the system ismaintained in equilibrium and in complete readiness for the next cuttingoperation without the hazard of a surge or sudden excess delivery'ofpowder when next cutting operation is begun.

It will be understood that such modifications and changes as willsuggest themselves to ,those skilled in the art which come within thetrue spirit of this invention are included as being within the scope ofthis invention best defined in the appended claims. I

This application is a continuation of our application Serial No. 317,912filed October 31, 1952, now abandoned, and is substituted therefon. i

Weclaimr I r 1.- Apparatus for thermochemically cutting metal by theaction of heating flames, a high pressure oxygen stream, and powderedadjuvant material delivered to the work with a carrier gas derived froma source thereof under pressure, comprising incornbination theewith ahopper normally closed to atmosphere for containing a supplyof powderedadjuvant material} and provided with a gas inlet and an outlet, apressure regulating valveupstream of said gas inlet'for maintaining saidadjuvant material "under a constant predetermined gas pressur e, conduitmeans including said outlet and an injector for effecting theentrainment 'of said adjuvantmateri'al in said carrier gas and fordelivering said material and the carrier gas to the work, aportion ofsaid, conduit means for deliveringcarrier gas only fromthesource'thereof to the injector, a first valve-in said portion of theconduit means, motivating means. for operating said valve; to regulatethefflow of carrier gas through said portion of the conduit means and ofadjuvant material 'throughlthe remainder of said conduit means, anda'second valve in said remainder of the conduit means simultaneouslyoperable with said first valve by said motivating means, said valvesinsuring without loss of carrier gas the maintenance of said constantpredetermined gas pressure on the supply of adjuvant material containedin said hopper when the adjuvant material is not flowing.

2. Apparatus for thermochcmically cutting metal by the action of heatingflames, a high pressure oxygen stream and powdered adjuvant materialdelivered to the work with aicarrier gas derived from a source thereofunder pressure, comprising in combination therewith a hopper normallyclosed to atmosphere for containing a supply of powdered adjuvantmaterial and provided with a' gas inlet and an outlet, a pressureregulating valve upstream of said gas inlet for maintaining saidadjuvant material under a constant predetermined gas pressure, conduitmeans including said outlet and an injector for effecting theentrainment of said adjuvant material in said carrier gas and fordelivering said material and the carrier gas to the work, a portion ofsaid conduit means for delivering carrier gas only from the sourcethereof to the injector, a first valve in said portion of the conduitmeans, motivating means for operating said valve to regulate the flow ofcarrier gas through said portion of the conduit means and of adjuvantmaterial through the remainder of said conduit means, and a second valvein said remainder of the conduit means simultaneously op: erable withsaid first valve by said motivating means, said valves for starting andstopping the flow of carrier gas and of adjuvant material and forinsuring without loss of 'carriergas the maintenance of the constantpredetermined gas pressure on the supply of adjuvant materialcontainedin said hopper when the adjuvant material is not flowing bypreventing gas from passing through the injector, said supply ofadjuvant material contained in said hopper being at a constantpredetermined lesser pressure than the pressure of the carrier gas insaid portion of the conduit means.

3. Apparatus for thermochemically cutting metal by the action of heatingflames, a high pressure oxygen stream, and powdered adjuvant materialdelivered to the Work with a carrier gas derived from a source thereofunder pressure, comprising in combination therewith a hopper normallyclosed to atmosphere for containing a supply of powdered adjuvantmaterial and provided with a gas inlet and an outlet, a pressureregulating valve upstream of said gas inlet for maintaining saidadjuvant material under a constant predetermined gas pressure, conduitmeans including said outlet and an injector for elfecting theentrainment of said adjuvant material in said carrier gas and fordelivering said material and the carrier gas to the work, a portion ofsaid conduit means for delivering carrier gas only from the sourcethereof to the injector, a first valve in said portion of the conduitmeans, motivating means comprising a pneumatic device operable underpressure from the high pressure oxygen stream for operating said valveto regulate the flow of carrier gas through said portion of the conduitmeans and of adjuvant material through the remainder of said conduitmeans, and another valve in said remainder of the conduit meanssimultaneously operable with said first valve by said pneumaticmotivating means, said valves insuring without loss of carrier gas themaintenance of the constant predetermined gas pressure on the supply ofadjuvant material contained in said hopper when the adjuvant material isnot flowing.

4. Apparatus for thermochemicallycutting metal 'by the action of heatingflames, a high pressure oxygen stream, and powdered adjuvant materialdelivered to the Work with a carrier gas derived from a source thereofunder pressure, comprising in combination therewith a hoppernormallyclosed to atmosphere for containing a supply of powdered adjuvantmaterial and provided with a gas inlet and an outlet, a pressureregulating valve upstream of said gas inlet for maintaining saidadjuvant material under a constant predetermined gas pressure, conduitmeans including said outlet and an injector for effecting theentrainment of said adjuvant material in said carrier gas and fordelivering said material and the carrier gas to the work, a portion ofsaid conduit means for delivering carrier gas only from the sourcethereof to the injector and a second portion of said conduit means forcarrying adjuvant material from said injector, a first valve in saidportion of the conduit means, and a second valve in said second portionof the conduit means downstream of said injector, said valves forcontrolling the flow of. 10 said carrier gas and an adjuvant materialand for insuring without loss of carrier gas the maintenance of theconstant predetermined gas pressure on the supply of adjuvant materialcontained in said hopper by preventing gas from passing through theinjector, pneumatically operable piston means connected to both of saidvalves for simultaneous operation thereof, and a high pressure oxygenstream torch valve, said pneumatically operated piston means beingoperable by pressure from said high pressure oxygen stream downstream ofsaid torch valve.

References Cited in the file of this patent UNITED STATES PATENTS806,904 Mullin Dec. 12, 1905 2,491,440 Boedecker et al Dec. 13, 19492,608,446 La Pot-a Aug. 26, 1952 2,622,548 Chouinard et a1. Dec. 23,1952

